Dual phase skin cosmetic compositions are currently very popular, in that they provide a broad range of cleansing/conditioning potential within a single product, and are also aesthetically appealing to the consumer. Typically, the dual phase product contains an aqueous phase and an oil phase, each adapted to removing a particular type of residue from the skin, or delivering a particular type of active. In a common use, for example, the aqueous phase of a dual phase cleansing composition is designed to remove water-soluble material from the skin, while the oil phase is designed to remove oil-based, or “waterproof” material from the skin.
A number of factors must be considered in making a successful dual phase product. For example, in order to function properly, the two phases must be vigorously mixed, providing a temporary apparently homogeneous single phase product which delivers both phases to the region to be treated simultaneously. This typically means that the product must contain one or more surfactants or emulsifiers, which will render the two phases at least temporarily compatible during the mixing and application stage. Surfactants are also frequently useful in the removal of waterproof makeup. Unfortunately, many such emulsifiers are drying to the skin and/or are irritating to users, and in particular cannot be routinely used in the eye area.
On the other hand, however, it is also desirable that the two phases separate quickly after use, as the emulsified product has a cloudy appearance that is unappealing to consumers. After prolonged, continuous mixing of the two phases during regular use, the time it takes for the phases to separate becomes longer and longer, and the product rapidly loses its initially attractive appearance. Moreover, oil soluble actives may be unstable if they remain in prolonged contact with the aqueous phase, and therefore, the amount of time spent in contact with the water phase should be minimized. As can readily be seen, these two aspects of the dual phase product, namely, the need for rapid and complete emulsification followed by rapid and complete separation, are at odds with each other, and to achieve both satisfactorily in a single product, in a way that is both cosmetically acceptable and attractive to the user, is often difficult. The present invention, however, provides a dual phase product in which the phases mix well and completely, and yet demixing is accomplished rapidly after use. Moreover, the product is non-irritating, and when used as a makeup remover, is highly successful in removing even the most difficult to remove oil-based cosmetics.